CANCER RISK--ENVIRONMENTAL EXPOSURE TO NITRATE /PESTICID

癌症风险——环境中暴露于硝酸盐/农药

• 批准号: 6420484
• 负责人: MARY H WARD
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6420484
• 关键词: United States; bladder neoplasm; brain neoplasms; cancer risk; colon neoplasms; environment related neoplasm /cancer; environmental exposure; esophagus neoplasm; human data; kidney neoplasms; nitrates; nonHodgkin's lymphoma; pancreas neoplasms; pesticide biological effect; pesticides; rectum neoplasms; rural area; stomach neoplasms; water pollution; water supply

Risk factors for cancer from agricultural exposures in the ambient environment are studied to estimate the contribution of these environmental exposures to cancer in the rural population. Rural populations have exposures to pesticides and nitrates in drinking water that are intermediate between occupationally-exposed groups and the general population. Case-control studies have been conducted on non-Hodgkin's lymphoma and cancers of the brain, bladder, colon, rectum, stomach, esophagus, pancreas, and kidney. Databases of water contaminants, gathered for routine monitoring purposes, are being used to estimate past exposures via public water supplies to individuals in these case-control studies. Elevated nitrate levels in public drinking water supplies were associated with an increased risk of non-Hodgkin's lymphoma in Nebraska. An analysis of nitrate in drinking water in Minnesota where exposure levels were lower found no association. This hypothesis is being investigated further in ongoing case-control investigations of non-Hodgkin's lymphoma in Iowa. The issue of nitrate as a cancer risk factor is being pursued further in an ecologic study encompassing twelve states in the United States and in a census-block group analysis in the Platte River Valley of Nebraska and Colorado, where elevated nitrate levels are among the highest in the country. We are also developing new approaches, and improving existing methods, of exposure assessment in studies of general environmental exposures, with a focus on pesticides and nitrate. These are required to better estimate risk and to detect the relatively small increases in risk often encountered in such studies. Geographic information systems (GIS) are being utilized for developing new approaches to estimating indirect exposure to pesticides and for estimating exposure to nitrates and pesticides in private wells. Remote sensing data (satellite imagery) and historical records were used to estimate the population in Nebraska potentially exposed to agricultural pesticides through the proximity of their homes to agricultural land treated with pesticides. This approach is also being used to improve pesticide exposure assessment in California in conjunction with the State pesticide use reporting database. Validation studies are underway to determine the relationship between pesticide levels in the home and the proximity to agricultural land where pesticides have been applied. Nitrate levels in private wells are being estimated using data on land cover, livestock feedlot locations, soil type, and other information.

研究环境中农业暴露的癌症危险因素，以估计这些环境暴露对农村人口癌症的贡献。农村人口在饮用水中接触杀虫剂和硝酸盐的程度介于职业接触群体和一般人群之间。对非霍奇金淋巴瘤和脑癌、膀胱癌、结肠癌、直肠癌、胃癌、食道癌、胰腺癌和肾癌进行了病例对照研究。在这些病例对照研究中，为例行监测目的收集的水污染物数据库被用来估计过去通过公共供水对个人的接触。内布拉斯加州公共饮用水中硝酸盐含量升高与非霍奇金淋巴瘤风险增加有关。对暴露水平较低的明尼苏达州饮用水中硝酸盐的分析发现没有关联。这一假设正在爱荷华州正在进行的非霍奇金淋巴瘤病例对照研究中得到进一步的研究。硝酸盐作为癌症风险因素的问题正在一项涵盖美国12个州的生态学研究中得到进一步探讨，并在内布拉斯加州和科罗拉多州的普拉特河谷进行了一项人口普查小组分析，那里的硝酸盐水平升高是全国最高的。我们还在开发新的方法，并改进现有的方法，在一般环境暴露研究中进行暴露评估，重点是农药和硝酸盐。这是为了更好地估计风险，并发现在此类研究中经常遇到的相对较小的风险增加。目前正在利用地理信息系统开发新的方法来估计间接接触杀虫剂的情况以及估计私人水井中硝酸盐和杀虫剂的情况。利用遥感数据（卫星图像）和历史记录来估计内布拉斯加州的人口，他们的家靠近农药处理过的农田，因此可能暴露于农业农药。与州农药使用报告数据库一起，这种方法也被用于改进加利福尼亚州的农药接触评估。正在进行验证研究，以确定家中农药水平与已施用农药的农田附近的关系。利用土地覆盖、牲畜饲养场位置、土壤类型和其他信息来估计私人水井中的硝酸盐水平。